On the Lp–Lq maximal regularity for Stokes equations with Robin boundary condition in a bounded domain

We obtain the L_p–L_q maximal regularity of the Stokes equations with Robin boundary condition in a bounded domain in ?ⁿ (n?2). The Robin condition consists of two conditions: v ? u=0 and αu+β(T(u, p)v – 〈T(u, p)v, v〉v)=h on the boundary of the domain with α, β?0 and α+β=1, where u and p denote a velocity vector and a pressure, T(u, p) the stress tensor for the Stokes flow and v the unit outer normal to the boundary of the domain. It presents the slip condition when β=1 and non‐slip one when α=1, respectively. The slip condition is appropriate for problems that involve free boundaries. Copyright © 2006 John Wiley & Sons, Ltd.     

Validation of a method for predicting the precision, limit of detection and range of quantitation in competitive ELISA.

The mathematical model for predicting the precision, limit of detection (LOD) and range of quantitation (ROQ) in a competitive enzyme-linked immunosorbent assay (ELISA) proposed by Hayashi et al. (Anal. Chem., 2004, 76, 1295) was validated. The model describes the relative standard deviation (RSD) of concentration estimates by the RSDs of pipetting volumes of analyte, enzyme-conjugated antigen, antibody and substrate solutions, and the standard deviation (SD) of inherent absorbances between the wells in an ELISA plate. For 6 kinds of direct competitive ELISA kits, the LOD and ROQ predicted by the model agreed well with those obtained by experiments with real samples. It was also confirmed that the model is applicable to the prediction of uncertainty that depends on the pipetting error of the viscous antiserum solution. The model was demonstrated to be useful for estimating the LOD and ROQ of competitive ELISA.     

Security Applications of Optical Face Recognition System: Access Control in E-Learning

The educational system has gradually shifted from a face-to-face to an e-learning system, which has become prevalent in advanced countries with the advance of information technology, and connection of global networks. Accordingly, a growing demand is emerging for more reliable individual certification with technical precision in order to measure and record learning achievements and credentials of participants. The present system has a limit in terms of registration capacity, therefore, its accuracy has often been questioned. Against this background, an individual certification system is proposed particularly for access control in e-learning. Under our proposed system, a compact optical correlator for facial recognition is employed. This correlator was previously tested for of biometrics authentication accuracy and proved highly reliable, having recorded remarkably low error rates (below 1%). The recorded error rate is sufficiently robust that the system itself can be regarded as a valid and practical viable attestation system.     

Preparation of a cyclodextrin dimer linked with a bis(picolinyl)cystine moiety and its intra- and intermolecular inclusion behavior

A novel cyclodextrin (CD) dimer linked with a bis(picolinyl)cystine (Cys) moiety was prepared by the coupling of Boc-protected Cys with amino-modified CDs, followed by deprotection of the Boc groups and bispicolinylation. The dimer showed less affinity to an organic guest molecule compared to that of a native CD monomer. It was attributed to an intramolecular inclusion of the pyridine moiety into CD cavity. The dimer caused significant increase of its organic guest affinity by an addition of a copper ion. The included pyridine group may come out of a CD cavity to bind the copper ion and the two CDs included cooperatively and intermolecularly a guest molecule with high affinity.     

Preparation of Silica-Silk Fibroin-Polyurethane Composite Films via a Sol-Gel Route

A tetraethoxysilane (TEOS)-derived sol aged for 0 h–6 h at room temperature was mixed with a polyurethane (PU) matrix. A composite of silk fibroin (SF) powders and acrylamide (AAm) was dispersed in the sol-PU mixture and dried isothermally at temperatures between 25°C and 120°C to obtain composite films. Three competitive reactions take place, i.e., those between silica-silica, SF-PU and silica-organic phases, during formation of the composite films. These reactions determine the properties such as morphology and homogeneity of the composite films. IR absorption bands for amide groups (–CONH–), C=O (amide I, 1730 cm^–1) and N–H (amide II, 1530 cm^–1) become larger with decreasing aging time of TEOS-derived sol, or increasing drying temperature. DTA exothermic peak due to the thermal decomposition of SF-AAm composite, on the composite films prepared from the 0 h-aged sol or dried at more than 50°C, shifts toward higher temperature by 44 K or more than 63 K respectively, as compared to the SF-AAm composite. Shorter aging time of TEOS-derived sol and higher drying temperature increased the extent of dispersibility, among SF-AAm composite, PU and silica, to bring a composite film more homogeneous.     

Information theory of miniaturization advantages of column liquid chromatography for quantitative analysis

Summary The influences of decreasing column diameter and length on two analytical goals, the precision and solvent efficiency, in reversed-phase liquid-chromatography are studied. Low solvent consumption is one of analytical advantages of miniaturized columns and is shown to be quantitatively evaluated by the precision and solvent efficiency which are defined to be the total Shannon mutual information obtained from an assay and the information obtained in a unit solvent volume, respectively. Analysis of paraben food additives on a microbore column is taken as an example. In trace analysis, the relative standard deviation (RSD) of measurements theoretically derived from the precision is shown to approach to the observed ones.     

Genetic variability in the response of normal murine hematopoietic progenitor cells to extracorporeal photochemotherapy

Normal hematopoietic progenitor cells from 129S6/SvEv mice are substantially less sensitive to Merocyanine 540 (MC540)-mediated photodynamic therapy (PDT) than hematopoietic progenitors from sex- and age-matched C57BL/6 mice. When exposed to a combination of MC540 and light commonly used for the extracorporeal purging of hematopoietic stem cells, granulocyte/macrophage progenitors (CFU-GM) from C57BL/6 mice are depleted 7.9-fold whereas CFU-GM from 129S6/SvEv and (C57BL/6 x 129S6/SvEv) F1 mice are depleted 1.4- and 2-fold, respectively. The same rank order of sensitivity is also found with regard to unipotent progenitors of granulocytes and macrophages and with regard to early and late erythroid progenitors. The resistance of hematopoietic progenitors from 129S6/SvEv mice to MC540-PDT appears to be the result of reduced dye binding rather than the result of high levels of intracellular glutathione. These findings have practical implications for the design of preclinical tests of PDT in animal models. They may also provide a useful tool for future investigations into the molecular determinants of sensitivity to MC540-PDT.     

Prediction of measurement precision of apparatus using a chemometric tool in electrochemical detection of high-performance liquid chromatography

The relative standard deviation (RSD) of measurements in high-performance liquid chromatography with electrochemical detection (HPLC-ECD) was predicted by a chemometric tool based on the 1/f fluctuation model which is made up of white noise and a Markov process, called the Function of Mutual Information (FUMI) theory. FUMI theory can provide aprecise and reliable detection limit from a single measurement of noise and signal in HPLC-ECD. To obtain RSD (n = 5) for determination of (-)-epicatechin at five concentrations required 12.5 h, while the predicted RSD by FUMI theory required only 0.5 h (one measurement). Moreover, to trace the source of instrumental noise, power spectra of chromatographic baseline were used. Selection of a suitable apparatus in HPLC-ECD system, acquisition of RSD, and detection limits for determination of catechins by HPLC-ECD were simply and easily made by this chemometric tool within a very short time. The use of the FUMI theory for the prediction of measuring precision was more efficient and the optimization was less time-consuming to be suited for determination.